Removing the rectifiers is a good way to disconnect the audio section from the power supply to determine if the excessive current draw is due to a problem in the PS or audio sections. I can't remember any time that it's caused any problems.

22 ohm resistors are OK.

Are all of the FETs in the supply heating up?

If you have a scope... On the falling side of the gate drive waveform, is the waveform perfectly vertical down to at least 2v (check all gates)?

In the MA audio amp, didn't at least 1 or 2 survive so that you can get the value?

No Fets are heating up....
Its just switching,but abnormally.....no heat...

Maybe not switching on and off at the right times ,maybe core saturation

On the scope without Fets clean lines,
With Fets it looks clean powering up momentarly until protection shuts it down. Then it powers up again. And it just keeps on cycling.
TRansformer is buzzing during this abnormal cycling...
Pulling current very quickly though,,,,no heat

Originally posted by Perry Babin Removing the rectifiers is a good way to disconnect the audio section from the power supply to determine if the excessive current draw is due to a problem in the PS or audio sections. I can't remember any time that it's caused any problems.

I wouldn't try this on any MS series PG amps or with any amp that uses complex opto-coupler type feedback for amp protection. All these amps use balanced DC rails to turn on a opto-coupler with zener regulated DC voltage drop so a acknowledgment signal gets feedback to the PWM that the power supply is functional. If not the supply usually faults for what appears to be no good reason at all.So although I agree diode removal won't hurt anything, it can cause misleading symptoms that tend to cause confusion of the original issues, and unless the diodes are bad it can be a waste of time.
But here again I also rely heavily on a current limited power supply method of bench testing. Once you set your current limits on the bench supply nothing gets damaged as the 12 volt source will knuckle over into current limit at a very safe region and the amp under test will just shutdown as the 12 volt feed drops to zero.

I just can't see pulling things apart that are completely functional to begin with so I developed the above method rather then spending all that time pulling out perfectly good parts. It just seemed logical that if its not broken then don't fix it. Happy New Year everyone !